This proposal addresses the significant disparity in mental health problems, as well as availability of Evidence Based Treatment (EBT), between American Indians (AIs) and the general U.S. population. Limited treatment engagement and poor retention rates, commonly regarded as major barriers to mental health care, contribute to the problem of disparities in mental health disorder prevalence. Socioeconomic factors are predictors of reduced treatment engagement and premature, unplanned termination. These characteristics include: minority status, low income, lack of health insurance, lower educational attainment, negative attitudes about mental health care, and substance use (Edlund, 2002; Wang, Bergland, et al., 2005). This proposal focuses on research designed to develop strategies to deal with three significant causes of the disparities: (1) the lack of an evidence base for culturally appropriate treatment for AIs; (2) problems of engagement and retention of AIs in treatment; and (3) the salience of historical trauma. In this pilot study, we will explore he feasibility, acceptance and sustainability of a treatment engagement and retention strategy, the Historical Trauma and Unresolved Grief Tribal Best Practice (HTUG) to engage and retain AI adults in an EBT, Group Interpersonal Psychotherapy (IPT), that may be well suited for treating depression and related mental disorders in this population. HTUG focuses on grief resolution related to AI collective massive group trauma across generations, and has potential for engaging AIs in EBTs through acknowledging the negative effects of colonialism on well-being and reducing the stigma of mental health problems (Brave Heart, 1998; Brave Heart, 2003). We will examine multiple aspects of feasibility, including recruitment, randomization, engagement and retention of clients; recruitment, training, supervision and retention of clinicians; client an clinician acceptance of and satisfaction with HTUG and Group IPT, client and clinician perceptions of the appropriateness of the research measures for client screening, process monitoring and outcome measurement; client (and clinician) acceptance of measures for examining their fidelity to the research model, clinic costs in terms of finances, space use, training time for clinicians, and clinical and staff support costs for HTUG and Group IPT implementation. Long term, what is learned from this proposed research could have significant promise for reducing disparities in mental health treatment and disease burden across AI populations and in culturally unique, disadvantaged and poorly served populations in general.